b) Contact number on notice if you dont receive a call from owner determine what is going on.
c) Once foreclosed lender will possible pay you cash for keys without going thru eviction.
You need too investigate you are obligated to terms of executed lease till lender takes possession.
You should definitely contact your landlord about this notice on your door. But I disagree with the answer of withholding your rent & putting it in an escrow account. You must honor your rental or lease agreement. Just make sure you keep a record that you paid your landlord the rent agreed upon in the terms. If you do not honor your agreement, you can be kicked out, whether by the landlord who is in default, or the bank or entity that takes ownership. Also, you want to keep a good rental history for yourself and your future.
Let me know if I can help in any way!